RESPIRATION

Question 1

What is respiration?

Answer 1

the process through which ATP is produced to be used in metabolic pathways

Question 2

What are the 4 stages of respiration?

Answer 2

glycolysis
the link reaction
the krebs cycle
oxidative phosphorylation

Question 3

What is required for glycolysis?

Answer 3

Glucose , ATP and NAD

Question 4

Describe glycolysis:

Answer 4

occurs in the cytoplasm
-Glucose is PHOPHORYLATED
- Rearranged into FRUCTOSE
- Fructose is PHOSPHORYLATED
-HEXOSE (1,6) BIPHOSPHATE
-HB —> TRIOSE PHOSPHATE
-Triose phosphate is oxidised (loses H+)
-NAD becomes NADH
-2 ATP produced

Question 5

what is the product of glycolysis

Answer 5

4 ATP (2 net gain)
2 NADH
2 pyruvate

Question 6

what happens after glycolysis and pyruvate production in aerobic respiration ?

Answer 6

Pyruvate entes the LINK REACTION

Question 7

Define DEHYDROGENATION

Answer 7

removal of Hydrogen atoms

Question 8

Define DECARBOXYLATION

Answer 8

removal of carbon atoms

Question 9

Describe the Link reaction :

Answer 9

*occurs in the mithocondria
- pyruvate {3C} is oxided (dehydrogenation) + decarboxylated
-NAD –> NADH
-ACETATE {2C} is produced
-Acetate + Coenzyme A
-Acetylcoenzyme A is produced

Question 10

how many link reactions per glucose?

Answer 10

2

Question 11

products of link reaction per glucose

Answer 11

2 AcetylCoA
2 CO2
2 NADH

Question 12

ingredients of link reaction

Answer 12

2 pyruvate
2 NAD
2 CoA

Question 13

what is the product that enters the krebs cycle?

Answer 13

acetate

Question 14

Describe the Krebs cycle:

Answer 14

acetylCoA –> CoA released back into the link reaction to continue to process
- acetate {2C} + OXALOACETATE {4C} = citrate {6C}
- dehydrogenation (NADH )and decarboxylation (CO2)
- 5C molecule
-dehydrogenation and decarboxylation
-4C
-ATP production
-4C
-FADH2 production
-OXALOACETATE (4C)
-dehydrogenation (NADH)

Question 15

Kreb cycle products :
per turn?
per glucose?

Answer 15

3NADH 6NADH
1 FADH2 2 FADH2
1 ATP 2 ATP
2 CO2 4 CO2

Question 16

What happens after kreb cycle?

Answer 16

oxidative phosphorylation

Question 17

main structures and components of oxidative phosphorylation :

Answer 17

NADH
FADH
H+
Oxygen
electrons
electron transfer chain
ATP synthase

Question 18

first step of oxidative phoshorylation

Answer 18

oxidation of NADH and FADH2

Question 19

Describe oxidative phosphorylation:

Answer 19

1. NADH and FADH2 are oxidized –> NAD and FAD
2. Release of H ions
3. H ions split into e- and protons+
4. H protons concentration increases in the
   intermembrane space of mitochondria
   - H ions are then pumped in the ATP synthase AGAINST CONCENTRATION GRADIENT.
   -H ions goes through atp synthase to allow the functionin of it (get ADP and P together = ATP)
   - H in the matrix bind with O2 and electrons to produce H2O
   -O2 is the terminal electron acceptor
5. electrons travel through the electron transport chain (high energy holder protein to low energy holder protein)
6. as electron passes through the proteins it looses energy
7. protein go through OXIDATION-REDUCTION process
8. last protein –> electrons released into the matrix

Question 20

what is the electrochemical gradient

Answer 20

the difference of H+ ions concentration across two membranes, the concentration of H+ is greater in the intermembrane space compared to the matrix

Question 21

what is the function of H+?

Answer 21

to allow the functioning of ATP synthase

Question 22

what happens to H+ after being pumped through the ATP synthase?

Answer 22

binds with electrons and oxygen to produce H2O

pumped in the intermembrane space again.

Question 23

what is the electron donor

Answer 23

NADH and FADH2 since they release H+

Question 24

what in an electron acceptor

Answer 24

oxygen

Question 25

describe chemiosmosis

Answer 25

process by which the movement of H+ IONS across a semipermeable membrane generates ATP

Question 26

what is anaerobic respiration

Answer 26

respiration in absence of oxygen

Question 27

anaerobic respiration in animals

Answer 27

Glucose –> Pyruvate –> Lactate
while pyruvate is produced NAD is reduced and become NADH.
to allow the NADH to be reused in glycolysis , pyruvate accept 2 H+ ions (reduced) and becomes Lactate, NAD can be regenerated
process can be reversed as no atoms are lost and lactase dehydrogenase is available to reverse reaction, and small ATP is still used

Question 28

reason for anaerobic respiration

Answer 28

since there is no oxygen , ETC cannot function since it doesnt have the terminal electron acceptor (oxygen) , if the ETC cannot function there is an accumulation of NADH AND FADH2

Question 29

anaerobic respiration in yeast cells

Answer 29

pyruvate –> decarboxylation –> ethanal –> ethanal reduced –> ethanol
cannot be reversed as atoms are lost
decarboxylase enzyme cannot reverse

Question 30

what are the differences between ANR in animals and yeast cells.

Answer 30

animals dont have an intermediate molecule however yeast cells do (ethanal)
animals cells do not go through decarboxylation whereas yeast cell do
in animal cell pyruvate is reduced wheras in yeast cells ethanal is reduced

Question 31

what are other substrates that can be used for respiration

Answer 31

carbohydrates
lipids
proteins

Question 32

Phosphocreatine

Answer 32

A phosphate source in muscle cells

Question 33

ATP that doesnt involve electron transport chain

Answer 33

substrate-level phosphorylation

Question 34

how is ATP produced in the Krebs cycle

Answer 34

ADP+P
substrate level phosphorylation
enzyme catalysed reaction

Question 35

“explain how the rate of respiration can be calculated from the graph and their observation”

Answer 35

• rate is inversely proportional to the time taken for colour change , 1: time
• respiration is directly proportional to the rate of colour change

Question 36

“advantage of respiring both anaerobically and aerobically”

Answer 36

-despite no oxygen is viable, glycolysis can still continue
- to produce small amount of ATP